function ajax(oParam) {
	var oXhr, type, sUrl, async, sBody, fn;
	type = oParam.type ? oParam.type : 'GET';
	sUrl = oParam.url  ? oParam.url  : console.log('你必须传入URL！');
	async = oParam.async ? oParam.async : true;
	sBody = oParam.body ? oParam.body : null;
	fn = oParam.fn ? oParam.fn : null;


	if(window.ActiveXObject) {
		oXhr = new window.ActiveXObject('Microsoft.XMLHTTP');
	} else {
		oXhr = new XMLHttpRequest();
	}
	
	oXhr.open(type, sUrl, async);
	oXhr.onreadystatechange = function () {
		if(oXhr.readyState == 4 && oXhr.status == 200) {
			if(fn) {
				fn(oXhr.responseText);
			}
		}
	}
	if(type.toLowerCase() == 'post') {
		oXhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	}
	oXhr.send(sBody);
}